It was electricity and gas supplier and retailer which primarily supplied the Sydney, Newcastle and Central Coast areas of New South Wales.

In 2005, EnergyAustralia formed a partnership with International Power to operate the retail business in Victoria and South Australia.

The electricity distribution network covered most of the eastern parts of Sydney, Central Coast and Hunter regions, with the Integral Energy distribution network covering most parts of Western Sydney.

TCA also includes a high power facility at Lane Cove, a NATA registered instrument calibration facility and was involved in electrical safety compliance testing of appliances until this division was closed in 2010, with the capability being sold to Vipac.

The metering services, Lane Cove High Power Testing Station and instrument calibration facility were later rebranded to PLUS ES.